1C04 Nonlinear Dielectric Behavior of Main-Chain Polymer Ferroelectric Liquid Crystal BB-4^* (2Me) /BB-6

Abstract

The main-chain liquid crystalline copolyester BB-4^* (2-Me) /BB-6 consisting of a biphenyldicarboxylic acid and equimolar mixture of chiral 2-methylbutanediol and hexanediol was examined by means of nonlinear dielectric spectroscopy. The Debye relaxation of the linear permittivity associated with the Goldstone mode motion is accompanied by the characteristic spectra of the third order nonlinear permittivity extending over the three quadrants on the complex plane. The charge response induced by a step-wise electric field exhibits a clear indication of ferroelectric polarization switching. These results substantiated that BB-4^* (2-Me) /BB-6 possesses a ferroelectric character associated with the Sc^* phase despite possible restrictions of mesogen motion by alkylene groups.